This invention relates to electric toasters, and more particularly to an improved safety device for an electric toaster for arresting operation of the toaster in the event of a jammed food item.
Household toasters commonly have a control chamber separated from a toasting chamber by a vertical end wall. A bread carriage plate is slidably received on a support post in the control chamber and carries a pair of bread lifters that extend into the toasting chamber between heating elements. The carriage plate and bread lifters are vertically movable between a raised position for loading bread or other food items onto the bread lifters and a lowered position for toasting the bread or other food items.
Some toasters have only one bread lifter while other toasters have two or more bread lifters. For the purpose of discussion, this invention is disclosed for use in a toaster configuration comprising two bread lifters, which is currently the most common. However, as will become apparent, aspects of this invention described below can be used in other toaster configurations.
In many toasters, the bread lifters are connected to a vertically movable support carriage. A coil spring biases the support carriage upwardly so that the bread lifters are normally in an upper, non-toasting position. The support carriage can be lowered to the toasting position by manipulation of a control lever accessible from outside the toaster housing. During a toasting cycle, a latch mechanism holds the support carriage and thus the bread lifters in a lowered, toasting position. User-adjustable electric means controls the toasting cycle times during which the bread lifters are latched in the toasting position in order to toast the food items to a desired color.
Some toasters include a lost-motion safety device wherein the bread is lowered by the support carriage onto holding tabs that extend from a sheet metal base of the toaster. The tabs are formed by stamping U-shaped slots in the sheet metal base then bending the tabs to form cantilevered supports. Once the bread is supported on the holding tabs, the support carriage can continue to descend until locked or latched in a toasting position, whereupon heating elements are energized to toast the bread. Should the bread become lodged at the end of a heating cycle, the support carriage will move upward to de-energize the heating elements before it contacts the bread to thereby stop the toasting cycle before the bread reaches an unpleasant state.
There is a continuous need to improve toaster mechanisms and their method of manufacture to realize further cost savings while maintaining safety standards. Accordingly, it would be advantageous to provide a toaster with an improved safety device that does not rely on lost motion mechanisms for stopping the toasting cycle in the event of a food jam.
According to the invention, an electric toaster comprises a chassis with at least one toasting compartment. At least one heating element is located in the compartment and a food support member is positioned in the compartment for supporting a food item. The food support member is biased toward an upper rest position and is movable between a lower toasting position and the upper rest position. An electromagnet is connected to the chassis for holding the food support member in the lower toasting position when energized. At least one switch is movable between a closed position to thereby energize the at least one heating element and an open position for deenergizing the at least one heating element. A rotatable support beam is pivotally connected to the chassis for pivotal movement between a first pivot position wherein the rotatable support beam moves the switch to the closed position and a second pivot position wherein the switch is in the open position. An armature is connected at a first end of the rotatable support beam for pivotal movement with the rotatable support beam between the first and second pivot positions. The armature is held by the electromagnet in the first pivot position when the electromagnet is energized and is separated from the electromagnet in the second pivot position when the electromagnet is deenergized. A first locking member is located at a second end of the rotatable support beam opposite the first end. A second locking member is operably connected to the food support member for movement therewith. In this manner, the first and second locking members interengage and the rotatable support beam is pivoted toward the first pivot position when the food support member is moved toward the lower toasting position to thereby close the switch and energize the at least one heating element. Upon energization of the electromagnet, the food support member is held against movement in the lower toasting position. Upon deenergization of the electromagnet, the rotatable support beam pivots to the second pivot position to disengage the first and second locking members and open the switch to deenergize the at least one heating element independent of movement or non-movement of the food support member.
Further according to the invention, safety shut-off device is provided for an electric toaster having a food support rod movable in a toasting chamber between an upper rest position and a lower toasting position and at least one heating element located in the toasting chamber. The safety shut-off device comprises a switch movable between a closed position to thereby energize the at least one heating element and an open position for deenergizing the at least one heating element. A rotatable support beam is pivotally connected to the chassis for pivotal movement between a first pivot position wherein the rotatable support beam moves the switch to the closed position and a second pivot position wherein the switch is in the open position. An armature is connected at a first end of the rotatable support beam for pivotal movement therewith between the first and second pivot positions. A first locking member is connected at a second end of the rotatable support beam opposite the first end for pivotal movement therewith between the first and second pivot positions. A second locking member is adapted for movement with the food support rod and is engageable with the first locking member in the lower toasting position for holding the food support rod in the lower toasting position. An electromagnet is fixedly positioned with respect to the armature for engaging and holding the armature when energized and releasing the armature when deenergized to thereby hold and release the food support in the lower toasting position. With this arrangement, the first and second locking members interengage and the rotatable support beam is pivoted toward the first pivot position when the food support member is moved toward the lower toasting position to thereby close the switch and energize the at least one heating element. Upon energization of the electromagnet, the food support member is held against movement in the lower toasting position. Upon deenergization of the electromagnet, the rotatable support beam pivots to the second pivot position to disengage the first and second locking members and open the switch to deenergize the at least one heating element independent of movement or non-movement of the food support member.